Ultracold nonreactive molecules in an optical lattice: Multichannel Hubbard models from chaotic collisions

Despite theoretically studying ultracold molecules in a lattice for a decade, the community has been using the wrong Hamiltonian. We recently derived the correct form of their effective lattice model [ PRL 116, 135301 (2016) ], which differs from the usual Hubbard model describing their atomic counterparts. Since then we have recently shown (via a variety of techniques) that the phase diagram for bosonic molecules is modified to include a large, unconventional region. In this region, there is a remarkable compressible liquid with a greatly suppressed condensate fraction, somewhat analogous to a "spin liquid" phase in quantum magnets or a "Bose glass" phase, but with no disorder.